Down Syndrome occurs when a person is born with an extra copy of the twenty-first chromosome. The syndrome gets its name from John Langdon Down, an English Physician. In 1866, he published the first accurate description of a person with Down Syndrome; However, it wasn’t until 1959 that Down Syndrome was identified as a Chromosomal condition. In 2000, scientists identified and catalogued the 329 genes on chromosome 21, opening the door to advances in Down Syndrome research.
Down Syndrome has no known causes other than the “something” that causes the extra copy of the twenty-first chromosome to be present in the genetic makeup of a child with down syndrome. It is a natural condition and is not caused by anything the mother did or didn’t do Unfortunately, there is also not much a woman can do to prevent having a child with Down Syndrome; however, according to the National Down Syndrome Society, the age of the mother at the time of conception is linked to having a child with Down Syndrome. As stated by the National Down Syndrome Society, “eighty percent of children with down syndrome are born to mothers under 35 years old”.
There are three different types of Down Syndrome. Trisomy 21 is the most common of the three. It occurs when there is an error in cell division and the baby ends up with three copies of chromosome 21 instead of two. This error is the result of nondisjunction. Before or at the time of conception a pair of cells in either the sperm or egg do not separate. This extra chromosome gets copied in every cell of the body as the baby grows.
The second least common form of Down Syndrome is Translocation. With Translocation there are still 46 chromosomes in all. The extra copy of the 21st chromosome is still present it is just attached to another, usually chromosome 14. The presence of the extra chromosome causes the features of Down Syndrome.
The least common type of Down Syndrome is Mosaicism. Mosaicism is diagnosed when there is a mixture of two types of cells, some of them just have 46 chromosomes and some of them have 47. The cells with 47 chromosomes have an extra chromosome 21. Researchers have found that people with mosaic Down Syndrome have fewer characteristics than people with other types; however, that cannot be exact because people with every kind of Down Syndrome have different abilities.
Down Syndrome is usually diagnosed at birth by certain features and characteristics; however there are tests to diagnosis the syndrome before birth. Chorionic villus sampling is a test before birth where cells are taken from the placenta and used to test the baby’s chromosomes. This test does not harm the baby and the chance of miscarriage is very low. Another test to be done would be Amniocentesis. During this test some of the amniotic fluid is taken from the mother’s uterus. They then use the fluid taken to test the chromosomes of the baby. This test is usually done after 15 weeks of pregnancy. There is also a test that can be done after birth called a chromosomal karyotype. This test requires a blood sample in which the cells are tested for an extra 21st chromosome.
A person with down syndrome may have decreased or poor muscle tone, short neck with excess skin at the back of the neck , flattened facial profile and nose, small head, ears, and mouth, upward slanting eyes, with a skin fold that comes out from the upper eyelid and covers the inner corner of the eye,
Burchfield spots, wide, short hands with short fingers, a single, deep, crease across the palm of the hand, and a deep groove between the first and second toes. When a baby is diagnosed with down syndrome from the characteristics listed or some other type of testing, they will have it for the rest of their life. There is no treatment for any type of down syndrome, but special adaptations to make life easier can be made.
Children with Down Syndrome have a higher chance of infection, respiratory, vision, and hearing problems. Forty percent of children affected with Down Syndrome have congenital heart defects, because of this it is important that all babies born with Down Syndrome have tests done on their hearts to find any heart defects as soon as possible. With the right care, people who have Down Syndrome live healthy lives. The life expectancy of a person with Down Syndrome is usually sixty years; however with the right care the person could live well into their seventies.
Even though children and adults with Down Syndrome may have developmental delays, they also have many talents and gifts and should be given the chance to improve on and display those talents. Most children with Down Syndrome have mild to moderate impairments, but they are more like other children than people know or think. Early intervention, such as physical, speech, and developmental therapies, should be started soon after the baby is born because this raises their chance for a normal productive life in society.
There are societies, organizations, and other resources to help people and families affected by down syndrome. There are several National Down Syndrome Organizations in the U.S. including the Global Down Syndrome Foundation, a National Down Syndrome Congress, and the National Down Syndrome Society. All of these organizations help to give information, support and advocacy along with improving the lives and promoting acceptance of people with Down Syndrome.